• The gestation being completed, labour, or the pains so denominated, is the natu ral process by which the child is forced into the world.
. There is some little variance in the term of gestation of different women ; at least the regularity in the human species does not equal that which we behold in other animals. The usual term is forty weeks or nine calendar months ; and the period from which the time ought to be dated, is a middle point between the antecedent and succeeding times of menstruation. The Roman law allows ten months to le gitimate parturition, or, in other words, ten months after the death ofthe husband. Hippocrates, upon whose opinion this law was probably founded, allowed this term, in like manner, as its utmost stretch, and would not extend it a moment beyond. The Old French law (for the present may perhaps vary) was coextensive. Yet Hal ler gives instances, which it is difficult not to credit, of eleven, twelve, and even more than twelve months ; whence the law of England is wisely silent upon the subject, and chooses rather to trust to the fair professional opinion and observation of the day, in connection with collateral cir cumstances, than rashly and abruptly to ruin a female reputation upon a moot and controverted point.
It is a law of nature, that about this pe riod of time the foetus should be expelled from the womb, and hence, whether liv ing or dead, whether light or bulky, whe ther the uterus lbe strong or feeble, the fcetus is expelled. A thousand causes
have been assigned for expulsion at this rather than at any other period, but not one of them appears to hold. It is a law of nature, and we know nothing beyond.
Labour then is intended to expel the child and its membranes from the uterus; and from the variety of phenomena it pre sents, it has usually, and may convenient. ly be divided into three classes : natural, difficult, and preternatural.
In the first kind the head presents, and the pains progressively increase, and in consequence of such increase, by pressing the head against the orifice of the uterus, gradually enlarge it, by which it becomes protruded into the vagina : the same co ercive power being exercised over which, the head of the child is shortly afterwards protruded into the world. The whole process is completed within twenty-four hours at the utmost, and is unaccompa nied with difficulty or danger. • In the class of dijfeult labour., the head indeed still presents; but the term is pro tracted beyond this period from acciden tal circumstances, that render it doubtful whether the life of both the mother and child can be preserved : or are else ac companied with other accidents, as twin cases, floodings, convulsions, rupture of the uterus.
The class ofpreternatura/ labours includes every presentation besides that of the head, or that of the head itself in conjunc tion with an upper or lower extremity.